We could choose any two quantities, and, in fact, it turns out that these are going to prove, after we have the second law, not to be the best choice.

我们可以任选两个物理量，其实，在学习了热力学第二定律之后，我们可以证明，这样的选择并不是最好的。

麻省理工公开课 - 热力学与动力学课程节选